Samson MFG Evolution KeyMod Rail Review

I recently completed my second full AR-15 build (my first "modern" one since my last one was a Vietnam era repro) and I'm slowly working through reviews of the various parts I used.  About a week ago I posted a review of the installation of the 87 Industries PinBlock pinned gas block.  I'm happy to report that 800+ rounds later, it is still firmly attached and it functioned flawlessly.

Samson on the left, Troy on the right

One of the accessories I was really excited about testing was the Samson Manufacturing Evolution KeyMod handguard.  There were a couple of reasons for this: I've never used a modular handguard before, always a quad rail handguard; and this rail installs completely differently than my other free-float rail, so it was a chance to compare the two.

My other free-float handguard is a Troy Industries MRF-12" CX.  It installs utilizing a two part clamp and has an opening to fit around the fixed front sight base of the Colt 6920 it is installed on.  The biggest downsides to this design are diameter and installation.  Comparing the two rails, the Samson is simpler to install and has a much smaller felt outside diameter (while still maintaining a large inner diameter). 

Now that I can choose my own AR accessories (as opposed to having them dictated to me by a list from HQ), I've come to realize several things.  First, I like long handguards.  I have freakishly long arms and I feel like I get much more control when my vertical foregrip is located farther out on the rail than your standard CAR handguard allows.  For the record - yes, I do still run a VFG; I do not do the Costa/Haley/MagPul hold (although if you personally run the C-clamp or whatever it's called, the extended rail is also a plus for you).  Second, since I no longer run all the accessories I did in a previous life, the need for four continuous rails just fails to present itself in all but the most exceptional situations.  Removing those three extra rails not only lightens the handguard, but also makes it much more comfortable to grip and makes the accessories I do decide to attach fit closer to the handguard, leading to less protrusion and snagging.  Third, a free-floated extended rail lets me run my new favorite gas system (mid-length) while still keeping the extended rifle+ sight radius for my irons. 

With all this in mind, the 15" Evolution that I installed fit the bill pretty much perfectly.  It's lightweight, coming in at only 12.8 ounces, and is incredibly easy to install.  The packaging only contains four pieces: the rail, two bushings, and an Allen wrench.  If you watch the online installation video, installation should take you approximately 10 minutes from the time you open the package to the time you complete the install, and 7:26 of that is watching the video.  If you're an idiot like me and choose not to watch the video, it may take a little longer since you'll have to remove the improperly installed handguard, watch the video, and then re-install it (I put the thermal bushings on upside down).  Just watch the video...

I was initially concerned about the rail wobbling on the rifle after I installed it.  I mean, the rail literally dropped onto the rifle with no need to bang it or anything.  It freaked me out.  However, 800+ rounds later, there is zero evidence of movement in the rail.  The mounting system is very simple.  There are three screws that hold the rail - two to tighten it down, and a set screw to prevent any forward movement.  There are no torque specs for the rail.  The clamping area has two wings that the screws run through and tightening the screws down enough to make the wings touch provides all the pressure needed to keep the rail from moving. 

Speaking of simple mounting, the Evolution utilizes the standard AR-15 barrel nut.  I am a huge fan of rails that keep it simple like this.  Granted, removing a barrel nut isn't that hard, but removal and installation do require a few specialized tools (barrel wrench, torque wrench, breaker bar, and moly grease), and many first time AR owners may not have these on hand.  Many handguards that have a proprietary nut also have a proprietary tool to install said nut, so now we need another tool.  If you decide to switch to a different rail later, now you need another proprietary tool.  Plus, you're not just talking about removing the barrel nut, you also have to remove the gas block, and maybe your muzzle device as well, so you're talking about more tools, more time, and more money.  Are there some awesome proprietary rails?  Absolutely.  Can you get a rail that will do what you need it to do without all that hassle?  Um, yes, you're reading about one right now...  In fairness, the Evolution does require a low-profile gas block as opposed to a FSB, but more and more rifle/upper manufacturers are offering low-profile blocks as a factory option, so it should be very simple to find one that fits your needs.  If you build your own (which I did), it's even simpler.

Other features of the Evolution rail are its ability to fit a suppressor under the rail, just in case one of your Grail guns happens to be a Honey Badger build (which mine is).  If you run a gas piston system, especially the Adams Arms system, the Evolution was built with piston systems in mind and has the necessary clearance machined into the upper rail.  You still need to double check with your kit maker, as there are variations between the different gas piston kits, but it should fit most of the current piston systems.  Also, in addition to the KeyMod mounting system at the 3, 6, and 9, Samson's Evolution accessories will fit the "S" cuts in between for even more mounting options.  As a side note on the KeyMod slots, the handguard has a continuous curve throughout its circumference, which means there is a slight curve even on the KeyMod section as opposed to some rails that have a flat surface for accessories to press up against.  I mounted two different KeyMod accessories on the rail for my class - a Bravo Company sling mount and one of their Gunfighter Mod III vertical grips.  I noted zero movement in their placement with the curved surface.  Once my Elzetta light gets here, I will mount it and check for fit as well. 

Overall, I'm very pleased with the Evolution KeyMod.  I think it's a great rail for someone who is looking for a sturdy, easy to install option.  This is going to be my go-to gun for receiving and giving training from here on out, so I'll let you know about its performance as I continue to push it.

About the author:

X Echo 1 is a 10 year veteran of the US Coast Guard, where he has served at various units including the International Training Division and Maritime Security Response Team.  He has held qualifications including Deployable Team Leader/Instructor, Direct Action Section Team Leader, and Precision Marksman – Observer.  He has deployed/instructed on five continents and served in quick reaction force roles for multiple National Special Security Events in the US.  He can be contacted on Facebook and Instagram.